Rock drilling apparatus



Oct. 21, 1952 J. C. CURTIS ETAL ROCK DRILLING ARPARATUS s Shuts-sheet 1 Filed Oct. 14. 1948 mh mm i sh w a n EarlEMtlZZer 21, 1952 J. c. sunns ETAL 2,614,808

ROCK DRILLING APPARATUS Filed Oct. 14, 1948 3 Sheets-$heet 2 la ll IA IA I1 .H, [Q Ch 11h? n l lf lu w v Q L.

I n". fluent??? n lf T111 @7272 EarZEMaZZer :wumw 5 i Agra attorney Oct. 21, 1952 J. c. CURTIS ETAL 5 3 ROCK'DRILLING APPARATUS Filed Oct. 14,1948 s- Sheds-Sheet 5 atio rney Patented Oct. 21, 1952 ROCK DRILLING APPARATUS John 0. Curtis, Claremont, N. H., and Earl E.Miller, El Paso, Tex., assignors to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application October 14, 1948, Serial No. 54,514

4 Claims.

This invention relates to drilling apparatus and. more particularly to a mobile drilling apparatus having an adjustable supporting structure for supporting a hammer rock drill in various positions with respect to the work.

In the drilling of rock, a hammer rock drill mounted on a mobile base is usually employed for drilling blast holes at various locations in a rock face so that the explosive charges received in the holes, when fired, effect the dislodgment of a substantial portion of the rock face. Where the rock face is of substantial height blast holes must be drilled at relatively high points in the face and some difficulty has heretofore been encountered in supporting the hammer drill at such high locations. Also, when the rock face is blasted down, a substantial quantity of rock is thrown out and lays in a pile on the floor near the face, and some rock fragmentsor boulders of the pile are ofttimes huge and unwieldy, so that secondary drilling is necessary in order to reduce the size of such fragments. It is also sometimes desirable to support the hammer rock drill above the rock pile in order to enable drilling of the toe-holes in an advanced face. The present invention contemplates improvements over known types of drill supports in that a drill supporting structure having substantial length and a wide range of adjustment is provided for supporting the hammer drill with respect to the working face. As has been previously stated, such wide range of adjustment is desirable and necessary to reach over a pile of previously blasted rock to support the drill in positions to drill toe-holes near the floor level in an advanced. face and for secondary drilling purposes. Also such a wide range of advancement is necessary to enable drilling of blast holes in a rock face of substantial height.

The present invention, from a broad aspect, relates to an adjustable supporting structure for a hammer rock drill whereby the drill may be adjusted through a relatively wide range, both vertically and horizontally, relative to a rock face, to support the drill in various locations with respect to the work. From a more specific aspect, the invention may comprise a mobile base which carries a support swiveled on an upright axis to swing horizontally relative to the base and in turn carrying an inner jib or boom frame pivoted on the swiveled support on a horizontal axis to swing in vertical planes with respect thereto. Pivotally mounted at the outer extremity of the boom frame or jib is an extension arm, which may be called an extension jib, which is mounted to swing in vertical planes either with or relative to the inner boom frame or jib. Carried at the outerextremity of the extension jib is an elongated guide frame for a conventional hammer rock drill. Thus a wide range of adjustment for the hammer drill is afforded, enabling drilling of blast holes in the rock face at relatively high points and also enabling reaching over a pile of rock previously blasted down to drill toe-holes near thefloor level and to support the drill for secondary drilling purposes. Power devices may be provided for independently swinging the inner boom frame or jib and the outer boom frame or extension jib about their respective pivots and for rigidly locking the jibs in adjusted position against downward swinging movement. The swiveled support by which the boom frames or jibs are carried may be manually turned on its vertical axis relative to the base and manually locked in position.

An object of the present invention is to provide an improved rock drilling apparatus. Another object is to provide an improved adjustable supporting structure for a hammer rock; drill. These and other objects and advantages will, however, hereinafter more fully appear. I

In the accompanying drawings there is shown for purposes of illustration one form which the invention may assume in practice.

In these drawings:

Fig. 1 is a side elevational view of a rock drilling apparatus constructed in accordance with a preferred illustrative embodiment of the invention, showing the hammer drill supported in operating position above a rock pile.

Fig. 2 is a top plan View of the drilling apparatus shown in Fig. 1.

Fig. 3 is an enlarged vertical section taken on line 3-3 of Fig. 2.

Fig. 4 is a diagrammatic view illustrating the hydraulic fluid system.

Fig. 5 is a side elevational view similar to Fig. 1 showing the hammer drill in different elevated positions as respectively indicated in full and dotted lines.

Fig. 6 is a side elevational view, on a reduced scale, showing the hammer drill supported in position to drill a large rock fragment in accordance with a secondary drilling operation.

In this illustrative construction, as shown in the drawings, a mobile base I has a frame 2 mounted on rubber tired wheels 3 which may be traction and steering wheels. Evidently, the base may assume various forms and may be crawler mounted, track wheel or otherwise mounted, as desired.

wiveled on the forward portion of the base frame 2 is a support 4 and the base frame carries a vertical column 5, shown in dotted lines in Fig. 1, on which the support is swiveled to turn about an upright axis, in a manner fully disclosed in a copending application to J. C. Curtis, Ser. No. 563,579, filed November 15, 1944, now Patent 2,500,931, issued March 21, 1950, and owned by the same assignee as the present invention. Coaxial with the column 5 is a friction look, as described in the application above referred to, and operated by a hand wheel 6 for locking the swivelled support 4 in adjusted position. Pivoted on a horizontal axis at I on the swivelled support 4 to swing in vertical planes relative thereto is a boom frame or inner jib 8 and a fluid cylinder 9 is pivoted at I on a bracket I I secured to the boom frame or jib. The cylinder contains a reciprocable piston I2 having its piston rod I3 extending rearwardly from the cylinder and pivotally connected at Id to the swivelled support.

The inner boom frame or jib may assume various forms but herein desirably comprises a rear transverse tubular bearing element I5 pivotally mounted on a pivot rod I6 secured within lateral brackets ll at the opposite sides of the swivelled support l. Suitably secured, as by welding, to the rear tubular element I5 are tubular ide elements I8, I8 which are rigidly braced by cross brace elements l9 and 20. Suitably secured, as by welding, to the outer ends of the tubular side elements I8 is a tubular cross element 2I carrying a pivot rod 22.

An outer extension boom or jib 23, which may likewise assume various forms, is pivotally mounted at the outer extremity of the inner jib 8 and comprises rigid side frame elements 24, 24 pivotally mounted at the ends of the pivot rod 22 to swing in vertical planes on an axis parallel with the pivotal axis of the inner boom frame. Secured between the side elements 24 is a transverse pivot rod 25 which is surrounded by spacing sleeves 26. The forward portions of the side elements 24 diverge inwardly and rearwardly and have parallel front portions 21 supporting a cross bar 28. Pivotally connected to the pivot rod I 0 is a fluid cylinder 29 containing a reciprocable piston 30 having its piston rod 3I extending forwardly from the cylinder and pivotally connected at 32 to the pivot rod 25. The piston rod 3| pivotally engages the pivot rod 25 intermediate the spacing sleeves 26 in the manner shown.

The swivelled support 4 carries a fluid tank 35 and a hand pump 36, the latter being operated by a lever 31. Mounted on the support near the tank is a valve device 38 including conventional control Valves 39 and 40. As shown diagrammatically in Fig. 4, the valve 39 controls the flow of fluid under pressure from the pump through a conduit 4| to the fluid cylinder 9 and the valve 40 controls the flow of fluid under pressure from the pump through a conduit 42 to the fluid cylinder 23. The valves 39 and 40 may be positioned to trap fluid in the cylinders to lock the parts against downward swinging movement and may also be positioned to connect the cylinders through a return conduit 43 back to the tank to permit downward swinging of the boom frames at a controlled rate.

An elongated guide frame 45 is swivelly mounted on the cross bar 28 for swinging adjustment in vertical planes, and a clamp 46 is provided for rigidly securing the guide frame to the cross bar. The guide frame may have a usual swivel plate mounted in a saddle on the cross bar to permit horizontal swinging adjustment of the guide frame, as well as tilting adjustment. Slidably guided on the guide frame is a hammer rock drill 4'! of a conventional design embodying a fluid actuated hammer motor for percussive actuation of a drill steel 48. Carried at the forward end of the guide frame is a conventional drill steel centralizer 49, While mounted at the rear end of the guide frame is a fluid operated motor 50 which actuates conventional feeding means for moving the rock drill back and forth along the guide frame. The guide frame and drill may be similar to those disclosed in the J. C. Curtis Patent No. 2,338,625, patented January 4, 1944.

In this improved construction, the cross bar 28 carries at its outer ends swivelled clamps 5| adjusted by bolts 52 and each carrying a pointed bar 53 adapted for engagement with an extraneous abutment such as the ground surface, for steadying the outer boom frame during the drilling operation. Upon release of the bolts 52 of the clamps 51 the pointed bars may be adjusted endwise or angularly as desired, and when the clamp-bolts are tightened the pointed bars are rigidly locked in adjusted position.

The drilling apparatus may be propelled over the ground surface and steered by the traction and steering wheels 3 during travel of the apparatus from one working place to another. In Fig. 1 the apparatus is shown in operating position with respect to the rock face F with the boom frame 8 and 23 extending forwardly over the top of a pile of rock P which has been previously blasted down from the working face. The outer boom frame 23 is swung downwardly and rearwardly with its outer end in a relatively low position near the level of the ground surface, and the parts held in adjusted position by trapping of the fluid within the cylinders 9 and 29 under the control of the valves 39 and 40. The floor engaging bars 53 are adjusted into engagement with the ground surface to steady the outer boom frame during the drilling operation. By loosening the clamp 35 the drill guide frame 45 may be tilted into the desired position as indicated in full and dotted lines in Fig. 1. When the drill is in a position substantially midway between the full and dotted lines shown in Fig. 1 toe-holes may be drilled into the advanced face in a well known manner. If it is desired to drill blast holes in the working face at higher elevations as indicated in full and dotted lines in Fig. 5, the valve 40 may be positioned to supply fluid under pressure from the pump 36 to the cylinder 29 to effect swinging of the outer boom frame 23 upwardly about its pivot 22 relative to the inner boom frame 8. If it is desired to position the rock drill at a higher elevation, fluid under pressure may be supplied from the pump to the cylinder 9 to swing the inner boom frame 8 upwardly about its pivot 7 relative to the support 4. When the parts are in the desired adjusted position the valves 39 and 40 may be positioned to trap fluid in the cylinders 9 and 29 to lock the boom frames against downward swinging movement thereby rigidly to support the drill with respect to the work. When the working face has been shot or blasted down the rock is ofttimes in large fragments as shown in Fig. 6, thereby necessitating secondary drilling operations. At this time the boom frames are adjusted in .the position shown in Fig. 6 wherein they extend above the rock pile and the drill guide frame 45 is tilted into the position shown to enable drilling of blast holes in the large rock fragment. By operating the hand wheel 6 the lock for the swivelled frame 4 may be released to permit manual swinging of the boom frame structure horizontally with respect to the base and after appropriate lateral adjustment of the drill the lock may be applied firmly to secure the swivelled frame in adjusted position.

As a result of this invention an improved rock drilling apparatus is provided whereby a hammer rock drill may be adjusted through a relatively wide range of supported positions with respect to the work. By the provision of relatively swingable boom frames not only is a relative wide range of adjustment afforded but also the boom frame structure due to its great length may extend outwardly above a rock pile to enable drilling of anadvanced face. The elongated supporting structure for the drill enables ready positioning of the drill for secondary drilling purposes and during such operations the drill may be supported above the rock pile in positions to drill blast holes in large rock fragments or boulders which'have previously been shot down from the working face. The provision of fluid cylinders for independently swinging the boom frames about their respective pivots not only makes drill adjustment more easy and expeditious, but also provides means for rigidly locking the boom frame against downward swinging movement thereby rigidly to support the rock drill in drilling position with respect to the work. Other advantages of the invention will be clearly apparent tothose skilled in the art.

While there is in this application specifically described one form which the invention may swing about a parallel axis in vertical planes with and relative to said inner boom frame, said outer boom frame forming a continuation of said inner boom frame and extending a substantial distance outwardly beyond said inner boom frame, power devices for independently swinging said boom frames about their respective pivots, said outer boom frame carrying a cross bar at its outer extremity, and a drill guiding frame swivelly mounted on said cross bar for adjustment in vertical planes into different angular positions about an axis parallel with said axes and along which a hammer rock drill is guided for movement to and from the work.

2. A drilling apparatus as set forth in claim 1 wherein, a support is swivelly mounted on said base to turn relative thereto about an upright axis and said adjustable supporting boom is pivotally mounted on said swiveled support and is turnable horizontally with said support into different angular positions with respect to said base.

3. A drilling apparatus as set forth in claim 1 wherein, said power devices are fluid operated and each includes a fluid cylinder and manually operable valves are provided for respectively controlling the flow of operating fluid to and from i said devices and positionable to trap fluid in the assume in practice, it will be understood that this form is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What we claim as new and desire to secure by Letters Patent is:

1. In a rock drilling apparatus, the combination comprising a mobile base, an elongated adjustable supporting boom pivotally mounted on said base and extending forwardly a substantial distance in advance of said base, said boom including an inner boom frame pivotally mounted on said base to swing in vertical planes with respect thereto about a horizontal transverse axis, and an outer boom frame pivotally. mounted on the outer extremity of said inner boom frame to cylinders of said devices to lock said boom frames against swinging movement about their respective pivots. I l

4. A drilling apparatus as set forth in claim 1 wherein, adjustable supports are carried at the outer extremity of said outer boom frame at the opposite ends of said cross bar and are engageable with an extraneous abutment for steadying the outer overhanging portion of said elongated supporting boom.

. JOHN C. CURTIS. EARL E. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,371,344 Brackett Mar. 15, 1921 1,754,348 Browne Apr. 15, 1930 2,094,588 Curtis Oct. 5, 1937 2,104,341 Curtis Jan. 4, 1938 2,123,897 Holmes July 19, 1938 2,217,674 Curtis Oct. 115, 1940 2,338,625 Curtis Jan. 4, 1944 

